1231144540 has 48 divisors (see below), whose sum is σ = 2760871680. Its totient is φ = 460131840.

The previous prime is 1231144493. The next prime is 1231144543. The reversal of 1231144540 is 454411321.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231144543) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16257 + ... + 52216.

It is an arithmetic number, because the mean of its divisors is an integer number (57518160).

Almost surely, 2^1231144540 is an apocalyptic number.

1231144540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1231144540 is an abundant number, since it is smaller than the sum of its proper divisors (1529727140).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1231144540 is a wasteful number, since it uses less digits than its factorization.

1231144540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68542 (or 68540 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 1231144540 is about 35087.6693440872. The cubic root of 1231144540 is about 1071.7734992895.

Adding to 1231144540 its reverse (454411321), we get a palindrome (1685555861).

The spelling of 1231144540 in words is "one billion, two hundred thirty-one million, one hundred forty-four thousand, five hundred forty".